The present invention relates to an exosome analysis method, an exosome analysis apparatus, an antibody-exosome complex, and an exosome electrophoresis chip.
An exosome is a small lipid vesicle with a diameter of 30 nm to 100 nm, and is secreted as a fusion between an endosome and a cell membrane in body fluids such as blood, urine, and saliva from various cells such as tumor cells, dendritic cells, T cells, and B cells.
In some cases, an abnormal cell, such as a cancer cell, expresses unique protein in a cell membrane. Protein derived from a cell of a secretory source is expressed in a membrane surface of an exosome. For this reason, there is a possibility of determining the characteristics of the cell of the secretory source by analyzing protein on the membrane surface of the exosome in a body fluid, and to establish examination techniques through which it is possible to examine abnormality in a living body without performing a biopsy. The term biopsy refers to a clinical procedure to diagnose disease by collecting tissue from a lesion area and observing it using a microscope or the like.
Based on such an expectation, a method of analyzing a membrane surface of an exosome by capturing a CD63-positive exosome, labeling the captured exosome with a fluorescent-modified antibody, and performing measurement through flow cytometry, using a bead modified with an antibody to CD63 expressed on the membrane surface of the exosome as an antigen, has been proposed (see Non-Patent Document 1).